HIGH CURRENT VOLTAGE REGULATOR

Thread Starter

HEALEY

Joined Nov 10, 2004
5
HAVE EXISTING DC SUPPLY, UNREGULATED CAPABLE OF 20 vdc @ 85A. REQUIRE REGULATION IN RANGE 10vdc TO 15vdc, AT 75 A.! YEP 75 AMPERES. CANNOT FIND ANY LITERATURE. THANX FOR YOUR SUGGESTIONS.
 

mozikluv

Joined Jan 22, 2004
1,437
hi

as far as i know TOSHIBA has 12A (TA7812S), 7.5A by INTERNATIONAL RECTIFIER (IRU1175CMTR) and 7.5A by LINEAR TECH. (LT1083CP-12)

you can check with this manufacturers :)

the highest that i have done is a 25A regulated in parallel configuration. :)
 

vhneumann

Joined Dec 1, 2004
4
Hello,

There's a circuit at http://www.edn.com/article/CA434875.html that shows how to parallel integrated regulators. If you used LM350, at 3 amps each you would need 25 of them, plus diodes, capacitors. Also, as all ICs share the common terminal (tab in TO220, case in TO-3 package) they can be mounted on a single heatsink. Take note that for 25 devices, regulation terminal current amounts to 25X100uA=2.5 mA. Also, the circuit shown by EDN uses fixed regulators, common tab to ground, whereas using LM350 which needs two resistors to adjust voltage output you would need a common resistor coming out from the heatsink. Using a switching regulator with MOSFET pass transistor you might reduce power dissipation and size; don't know how to, but at the factory floor we use 24V 40A switching PSUs.

Best regards
 

vhneumann

Joined Dec 1, 2004
4
Hi there,

Check circuits and also some theory about PWM regulation at

http://www.edn.com/contents/images/31600di.pdf dimmer
http://us.st.com/stonline/books/pdf/docs/3566.pdf dimmer
http://users.pandora.be/educypedia/electro...uitsbypower.htm


You can regulate the secondary side, using low voltage, high current MOSFETS - IRFZ44 - or regulate the primary side, using a TRIAC. I can remember repairing a little beast at a mechanic's shop; it regulated the primary side of thr transformer using a VERY SIMPLE triac circuit and rectifying the secondary with many diodes in parallel. This thing was used to charge 24/48 V batteries, also as a starter for truck motors. It was too simplistic, missed current sharing resistors in series with each diode at the secondary side. Maybe you could try a similar idea and improving upon the thery at the preceding links.

Best regards
 
Top